Packing Density Necessary to Reach a High Complete Occlusion Rate in Circumferential Unruptured Intracranial Aneurysms Treated with Stent-Assisted Coil Embolization

R.T. Tosello; U.C. Batista; B.J.A. Pereira; R.L. Piske

doi:10.3174/ajnr.A5303

Abstract

BACKGROUND AND PURPOSE: This study is a homogeneous series of circumferential unruptured intracranial aneurysms with large necks treated with stent-assisted coil embolization. Our purpose was to demonstrate which value of packing density is required to produce a durable occlusion.

MATERIALS AND METHODS: We retrospectively evaluated all patients with unruptured intracranial aneurysms who were treated with stent-assisted coil embolization having late angiographic control between 2004 and 2014, in a single large cerebrovascular referral center. To calculate the packing density, aneurysm volume, and coil volume, we used an on-line system.

RESULTS: In 49 circumferential unruptured intracranial aneurysms treated with stent-assisted coil embolization, 38.7% (n = 19) had complete occlusion in the immediate control. Of those with incomplete occlusion, 80% (n = 24) progressed to complete occlusion in the late angiographic follow-up. At late angiographic control, 87.7% (n = 43) of aneurysms were completely occluded. All aneurysms with a packing density of ≥19% were completely occluded. Packing density was the only statistically significant predictor of complete occlusion. None of the aneurysms with complete occlusion at immediate control or at late angiographic control had recurrence.

CONCLUSIONS: In circumferential aneurysms treated with stent-assisted coil embolization, packing density is the main predictor of complete occlusion. In this type of aneurysm, a packing density of ≥19% was enough to reach complete occlusion; knowing this is important to avoid higher packing densities that have more risk.

ABBREVIATIONS:

PD: packing density
SACE: stent-assisted coil embolization
UIA: unruptured intracranial aneurysm

Unruptured intracranial aneurysms (UIAs) are present in 3% of the adult population and are increasingly detected due to more frequent use of noninvasive angiographic diagnostic imaging.^1⇓–3

Endovascular coiling for the treatment of intracranial aneurysms was first introduced into clinical use in 1990, and since then, the greatest concern has been the high recanalization rate, recently estimated to be approximately 20%.^4,5 This occurs more often in large-neck aneurysms,⁶ which are currently treated with stent-assisted coil embolization (SACE).

In unassisted coil embolization, higher packing density (PD) rates are correlated with lower recanalization rates.^7⇓⇓–10 It is likely that in SACE treatment, the packing density necessary to reach a stable complete occlusion is lower, but there is no homogeneous study to confirm that possibility, to our knowledge.

The purpose of this study was to demonstrate which value of PD is likely to produce durable occlusion in a homogeneous series of circumferential, large-neck UIAs treated with SACE in a single cerebrovascular referral center.

Materials and Methods

The study protocol was approved by a local institutional review board. This is a single-center retrospective review of our data bank from February 2004 to June 2014. Clinical and image records were independently reviewed by a member of the research team who did not participate in the treatment of any of the included patients. The patient demographics, treatment details and effects, results of follow-up, and complications were recorded.

All patients were treated under general anesthesia, and stent-assisted coiling was performed on a biplane Integris Allura FD20/30 angiographic system (Philips Healthcare, Best, the Netherlands). Regular techniques were used, including prior use of dual antiplatelet therapy.

From the 310 aneurysms in 271 patients treated with SACE, we selected 49 unruptured circumferential wide-neck aneurysms, not previously treated in 47 patients, with 3D reconstruction angiography before treatment and at least 1 late angiographic control. The mean time from the operation until the first follow-up was 7.0 months. Wide-neck aneurysms were defined as having at least 1 of the following criteria: neck size ≥ 4 mm, dome-to-neck ratio < 1.5, or a cylindric neck.

To calculate the packing density, volume of aneurysms, and volume of coils, we used an on-line system available at www.angiocalc.com. This calculation was based on the shape and size of the aneurysm and on the type and size of the coils. All aneurysms treated with coils that did not have calculations based on this site were excluded.

Of the 47 patients, 15 were men, and 32, women. The mean age was 56.7 years. Of the 49 aneurysms, 32 had wide necks (>4 mm), 42 had unfavorable dome-to-neck ratios (<1.5 mm), 26 had wide necks and unfavorable dome-to-neck ratios, and 2 had cylindric necks.

The relationship between the location and number of aneurysms is shown in Table 1.

View this table:

Table 1:

Relationship between the location and number of the aneurysms

Aneurysm obliteration rates on the immediate control and first follow-up angiograms were classified as complete (100%); any opacity in the neck or sac of the aneurysm was considered incomplete obliteration.

In the late angiographic control, we evaluated the rate of progression from incomplete to complete occlusion and whether there was recurrence of an aneurysm with initial complete occlusion. We compared these data with the location of the aneurysm, the volume of the aneurysm and coils, the PD, and the type of stent used.

We used 4 types of stents: the Neuroform stent (Stryker Neurovascular, Kalamazoo, Michigan) in 35 procedures, the LEO stent (Balt Extrusion, Montmorency, France) in 16 procedures, the Enterprise stent (Codman & Shurtleff, Raynham, Massachusetts) in 2 procedures, and the Solitaire stent (Solitaire AB neurovascular remodeling device; Covidien, Irvine, California) in 1 procedure.

Statistical Analysis

Statistical analysis was performed by using R statistical and computing software, Version 3.2.2 (http://www.r-project.org/). For the relationships between volume and packing and volume and incomplete occlusion, the Pearson correlation coefficient was calculated. To obtain the relationship among age, sex, aneurysm volume, packing density, and volume of coils and complete occlusion at 6-month follow-up, we used logistic regression. We also calculated the corresponding 95% confidence interval to verify the existence of the relationship. The relationships between a high percentage of PD and complete occlusion and between large aneurysms and incomplete occlusion were assessed with logistic regression analysis. P values < .05 indicated a significant difference.

Results

In the immediate control, complete occlusion occurred in 38.7% of aneurysms (n = 19), and incomplete occlusion, in 61.2% aneurysms (n = 30). However, of those who had incomplete occlusion, 80% (n = 24) progressed to complete occlusion and the remaining 20% (n = 6) had incomplete occlusion (Fig 1). At the late angiographic control, 43 aneurysms (87.7%) had complete occlusion. There was no aneurysm recurrence in the first follow-up for those aneurysms that were completely occluded in the immediate control.

Fig 1.

A 62-year-old man presenting with a small, incidental aneurysm of the anterior communicating artery. A 3D rotational angiogram (A) was obtained before the embolization. Measurements were made of the neck (blue line), diameter parallel to the neck (green line), height (red line), and largest diameter (yellow line). Projection work after a right internal carotid contrast injection (B) shows the relation of the anterior communicating artery aneurysm to the anterior cerebral arteries. Final control after simultaneous contrast injections in the internal carotid artery. C and D, Residual neck flow (white arrow) after stent-assisted coil embolization (stent, white arrows; coils, black arrow). Six-month angiographic controls (E and F) show the evolution to complete occlusion (black and white arrows).

The mean volume of the 49 aneurysms was 175.2 mm³ (median, 329.7 mm³; range, 4.2–4849.9 mm³). The mean coil volume was 38.5 mm³ (median, 54.7 mm³; range, 1.5–396.3 mm³), and the average PD was 37.9% (median, 28.6%; range, 2.8%–54.9%).

Above 19% of PD, all aneurysms were completely occluded, independent of their volume (Fig 2).

Fig 2.

Results of the Pearson test, demonstrating that above 19% packing density, all aneurysms had complete occlusion. Regarding the volume, aneurysms above 179.6 mm³ had a higher rate of incomplete occlusion when the packing density was below 19%. If >1 aneurysm is overlapping, note the following symbols: , 2 aneurysms, , 3 aneurysms, , 4 aneurysms.

According to Fig 2, the aneurysms were subdivided into 2 groups on the basis of volume: A, <179.6 mm³ (n = 37); B, >179.6 mm³. In group A, all aneurysms except 1 had complete occlusion, independent of their PD. The only aneurysm incompletely occluded in this group was one in which we could not deploy a necessary second coil due to the impossibility of recatheterizing the aneurysm sac after the first coil. In group B, complete occlusion was reached for all aneurysms with a PD of >19%. Aneurysms of >179.59 mm³ had a larger diameter, between 7.0 and 7.8 mm.

The statistically significant correlation coefficient (P < .05) between aneurysm volume and PD was −0.42 (95% CI, −0.62 to −0.15; P = .003), and the correlation between aneurysm volume and incomplete aneurysm occlusion was −0.44 (95% CI, 0.18–0.64; P = .002). The correlation coefficient between coil volume and PD was 0.26 (95% CI, −0.50 to 0.02; P = .071), which is not statistically significant. Large volumes of coils are used in large aneurysms, which tend to have lower PD.

A multivariate analysis with predictive factors of complete aneurysm obliteration, including age, aneurysm volume, PD, and volume of coils, showed that the only statistically significant predictive factor was PD (Table 2).

View this table:

Table 2:

Multivariate analysis of predictive factors for complete occlusion

Procedure-related complications occurred in 3 patients (6.4%, 3/47). In 2 patients (4.1%, 2/49), there was thrombosis of the stent after its release; one was treated with an intravenous infusion of a loading dose of abciximab (ReoPro), and the other, with an intra-arterial injection of tirofiban (Aggrastat) and mechanical thrombolysis, with full opening of the parent vessel. Both had a transient deficit and full recovery in 3 and 4 days, respectively. One patient (2.1%, 1/47) had an asymptomatic vertebral artery dissection, and a stent was placed at the site of dissection. There was no neurologic deficit in any of the 3 patients at discharge.

Discussion

Stent-assisted coil treatment for large-neck aneurysms has shown a higher rate of evolution to complete occlusion in the follow-up and a lower rate of late aneurysm recanalization compared with nonstented aneurysms.^{6,8,11⇓⇓–14} The mechanisms involved are hemodynamic modification of the inflow angle to the sac, the presence of more metal on the neck, and the scaffold provided by the stent and coils favoring better endothelialization.^6,15⇓–17 It is thought that the main predictor of immediate and late complete occlusion and the absence of aneurysm recurrence is the PD.^{8,11,12,18⇓⇓⇓–22}

However, we supposed that to achieve a higher PD, it is necessary to place several coils inside the aneurysm, increasing the treatment time, the risk of thromboembolic and hemorrhagic complications, and the cost of the procedure.

Gallas et al²³ found that 26% of aneurysms had an incomplete occlusion among 1036 aneurysms treated with coils. Raymond and Roy⁷ reported that incomplete occlusion in the immediate control of aneurysms treated with coils is a risk factor for aneurysm recanalization. Piotin et al¹¹ reported that aneurysms treated with SACE had lower recanalization rates than nonstented aneurysms. Lawson et al²² identified PD as a predictor of complete occlusion in aneurysms treated with SACE.

Chalouhi et al^8,13 found an adequate PD of 12%–22% for complete occlusion of aneurysms in angiographic follow-up tests in 290 aneurysms treated with SACE, but the aneurysm recurrence rate was not reported.

Unlike others, our study considered only circumferential saccular UIAs, homogenizing the group to find the PD required for a high complete aneurysm occlusion rate, with low rates of recurrence and complications during the procedure.

Our study presented a rate of 38.7% (n = 19) with complete occlusion and 61.2% (n = 30) with incomplete occlusion in the immediate control. Of those in the latter group, 80% (n = 24) progressed to complete occlusion in the late angiographic follow-up.

PD is the main predictor of complete occlusion and aneurysm recurrence. Our study found all aneurysms with PD ≥19% with initial incomplete occlusion evolved to complete occlusion in the late angiographic follow-ups, with a statistically significant relationship between the variable PD and the first follow-up, in agreement with the study of Chalouhi et al.⁸ Aneurysms with low PD (<19%) tended to not evolve to complete occlusion. None of the aneurysms that were completely occluded had recurrence, emphasizing the relevance of the flow-remodeling theory in the use of stents.^6,15⇓–17

However, aneurysms with smaller (<100 mm³) and moderate (100–1150.3 mm³) volumes had high rates of complete occlusion (96% and 85%, respectively), compared with aneurysms with greater volume (>1150.3 mm³), demonstrating that smaller aneurysm volume can reach a better PD value with higher complete occlusion rates than those of large aneurysms, as described in the literature.^{5,6,9,11,12,18,24} There was no statistically significant relation between the volume and packing density of an aneurysm: The P value was .079 (statistical significance, P < .05), probably due to the low number of aneurysms.

Sluzewski et al⁹ reported that all aneurysms with packing densities of >24% and a volume of <600 mm³, treated with coil embolization, had complete occlusion. We found that all aneurysms with packing densities of ≥19% independent of their volume had complete occlusion. This finding shows that stents help neck endothelization, requiring fewer coils to reach complete occlusion.¹⁷

No patient with complete occlusion in our study needed retreatment, and our complication rate was 6%. All patients were discharged without neurologic deficits and none died.

A limitation of our study is its retrospective, no randomization design in a single center with a small sample due to the inclusion of only circumferential UIAs. Another limitation is the use of a variety of regular stents and coils.

Today with the advancement of technology, new stents with lower porosity or double layers (eg, LVIS Blue, Lvis, Lvis Jr; MicroVention, Tustin, California) may produce different results, needing specific studies.

Conclusions

This study shows that the SACE technique has high rates of evolution from incomplete-to-complete occlusion of aneurysms, without recurrence. The PD is the main predictor for complete aneurysm occlusion. All aneurysms with PD of ≥19% achieved complete occlusion. For small aneurysms, the rate of complete occlusion was higher than in large aneurysms because it is difficult to achieve an optimal packing density in large aneurysms. The PD needed to occlude large-neck aneurysms treated with stents is lower than in those without stents.

References

1.↵
2. Wiebers DO,
3. Whisnant JP,
4. Huston J 3rd., et al
; International Study of Unruptured Intracranial Aneurysms Investigators. Unruptured intracranial aneurysms: natural history, clinical outcome, and risks of surgical and endovascular treatment. Lancet 2003;362:103–10 doi:10.1016/S0140-6736(03)13860-3 pmid:12867109
CrossRef PubMed
2.↵
2. Etminan N,
3. Brown RD Jr.,
4. Beseoglu K, et al
. The unruptured intracranial aneurysm treatment score: a multidisciplinary consensus. Neurology 2015;85:881–89 doi:10.1212/WNL.0000000000001891 pmid:26276380
CrossRef PubMed
3.↵
2. Seibert B,
3. Tummala RP,
4. Chow R, et al
. Intracranial aneurysms: review of current treatment options and outcomes. Front Neurol 2011;2:45 doi:10.3389/fneur.2011.00045 pmid:21779274
CrossRef PubMed
4.↵
2. Molyneux AJ,
3. Kerr RS,
4. Birks J, et al
; ISAT Collaborators. Risk of recurrent subarachnoid haemorrhage, death, or dependence and standardised mortality ratios after clipping or coiling of an intracranial aneurysm in the International Subarachnoid Aneurysm Trial (ISAT): long-term follow-up. Lancet Neurol 2009;8:427–33 doi:10.1016/S1474-4422(09)70080-8 pmid:19329361
CrossRef PubMed
5.↵
2. Mascitelli JR,
3. Oermann EK,
4. De Leacy RA, et al
. Predictors of treatment failure following coil embolization of intracranial aneurysms. J Clin Neurosci 2015;22:1275–81 doi:10.1016/j.jocn.2015.03.002 pmid:25986179
CrossRef PubMed
6.↵
2. Colby GP,
3. Paul AR,
4. Radvany MG, et al
. A single center comparison of coiling versus stent assisted coiling in 90 consecutive paraophthalmic region aneurysms. J Neurointerv Surg 2012;4:116–20 doi:10.1136/jnis.2011.004911 pmid:21990478
Abstract/FREE Full Text
7.↵
2. Raymond J,
3. Roy D
. Safety and efficacy of endovascular treatment of acutely ruptured aneurysms. Neurosurgery 1997;41:1235–45; discussion 1245–46 doi:10.1097/00006123-199712000-00002 pmid:9402574
CrossRef PubMed
8.↵
2. Chalouhi N,
3. Dumont AS,
4. Hasan D, et al
. Is packing density important in stent-assisted coiling? Neurosurgery 2012;71:381–86; discussion 386–87 doi:10.1227/NEU.0b013e31825c36dd pmid:22569059
CrossRef PubMed
9.↵
2. Sluzewski M,
3. van Rooij WJ,
4. Slob MJ, et al
. Relation between aneurysm volume, packing, and compaction in 145 cerebral aneurysms treated with coils. Radiology 2004;231:653–58 doi:10.1148/radiol.2313030460 pmid:15118115
CrossRef PubMed
10.↵
2. Chueh JY,
3. Vedantham S,
4. Wakhloo AK, et al
. Aneurysm permeability following coil embolization: packing density and coil distribution. J Neurointerv Surg 2015;7:676–81 doi:10.1136/neurintsurg-2014-011289 pmid:25031179
Abstract/FREE Full Text
11.↵
2. Piotin M,
3. Blanc R,
4. Spelle L, et al
. Stent-assisted coiling of intracranial aneurysms: clinical and angiographic results in 216 consecutive aneurysms. Stroke 2010;41:110–15 doi:10.1161/STROKEAHA.109.558114 pmid:19959540
CrossRef PubMed
12.↵
2. Chalouhi N,
3. Jabbour P,
4. Singhal S, et al
. Stent-assisted coiling of intracranial aneurysms: predictors of complications, recanalization, and outcome in 508 cases. Stroke 2013;44:1348–53 doi:10.1161/STROKEAHA.111.000641 pmid:23512976
Abstract/FREE Full Text
13.↵
2. Chalouhi N,
3. Starke RM,
4. Koltz MT, et al
. Stent-assisted coiling versus balloon remodeling of wide-neck aneurysms: comparison of angiographic outcomes. AJNR Am J Neuroradiol 2013;34:1987–92 doi:10.3174/ajnr.A3538 pmid:23639562
Abstract/FREE Full Text
14.↵
2. Hong Y,
3. Wang YJ,
4. Deng Z, et al
. Stent-assisted coiling versus coiling in treatment of intracranial aneurysm: a systematic review and meta-analysis. PLoS One 2014;9:e82311 doi:10.1371/journal.pone.0082311 pmid:24454690
CrossRef PubMed
15.↵
2. Tanemura H,
3. Ishida F,
4. Miura Y, et al
. Changes in hemodynamics after placing intracranial stents. Neurol Med Chir (Tokyo) 2013;53:171–78 doi:10.2176/nmc.53.171 pmid:23524501
CrossRef PubMed
16.↵
2. Tateshima S,
3. Tanishita K,
4. Hakata Y, et al
. Alteration of intraaneurysmal hemodynamics by placement of a self-expandable stent: laboratory investigation. J Neurosurg 2009;111:22–27 doi:10.3171/2009.2.JNS081324 pmid:19267529
CrossRef PubMed
17.↵
2. Lopes D,
3. Sani S
. Histological postmortem study of an internal carotid artery aneurysm treated with the Neuroform stent. Neurosurgery 2005;56:E416; discussion E doi:10.1227/01.NEU.0000147977.07736.66 pmid:15670395
CrossRef PubMed
18.↵
2. Geyik S,
3. Yavuz K,
4. Yurttutan N, et al
. Stent-assisted coiling in endovascular treatment of 500 consecutive cerebral aneurysms with long-term follow-up. AJNR Am J Neuroradiol 2013;34:2157–62 doi:10.3174/ajnr.A3574 pmid:23886748
Abstract/FREE Full Text
19.↵
2. Sadato A,
3. Adachi K,
4. Hayakawa M, et al
. Effects of anatomic characteristics of aneurysms on packing density in endovascular coil embolization: analysis of a single center's experience. Neurosurg Rev 2016;39:109–14; discussion 114 doi:10.1007/s10143-015-0658-7 pmid:26223542
CrossRef PubMed
20.↵
2. Ozretić D,
3. Radoš M,
4. Pavliša G, et al
. Long-term angiographic outcome of stent-assisted coiling compared to non-assisted coiling of intracranial saccular aneurysms. Croat Med J 2015;56:24–31 doi:10.3325/cmj.2015.56.24 pmid:25727039
CrossRef PubMed
21.↵
2. Bouillot P,
3. Brina O,
4. Ouared R, et al
. Particle imaging velocimetry evaluation of intracranial stents in sidewall aneurysm: hemodynamic transition related to the stent design. PLoS One 2014;9:e113762 doi:10.1371/journal.pone.0113762 pmid:25470724
CrossRef PubMed
22.↵
2. Lawson MF,
3. Newman WC,
4. Chi YY, et al
. Stent-associated flow remodeling causes further occlusion of incompletely coiled aneurysms. Neurosurgery 2011;69:598–603; discussion 603–04 doi:10.1227/NEU.0b013e3182181c2b pmid:21430583
CrossRef PubMed
23.↵
2. Gallas S,
3. Januel AC,
4. Pasco A, et al
. Long-term follow-up of 1036 cerebral aneurysms treated by bare coils: a multicentric cohort treated between 1998 and 2003. AJNR Am J Neuroradiol 2009;30:1986–92 doi:10.3174/ajnr.A1744 pmid:19679641
Abstract/FREE Full Text
24.↵
2. Yang H,
3. Sun Y,
4. Jiang Y, et al
. Comparison of stent-assisted coiling vs coiling alone in 563 intracranial aneurysms: safety and efficacy at a high-volume. Neurosurgery 2015;77:241–47; discussion 247 doi:10.1227/NEU.0000000000000765 pmid:25856112
CrossRef PubMed

Received March 6, 2017.
Accepted after revision May 18, 2017.

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Show more INTERVENTIONAL

[1] 1.↵

Wiebers DO,
Whisnant JP,
Huston J 3rd., et al
; International Study of Unruptured Intracranial Aneurysms Investigators. Unruptured intracranial aneurysms: natural history, clinical outcome, and risks of surgical and endovascular treatment. Lancet 2003;362:103–10 doi:10.1016/S0140-6736(03)13860-3 pmid:12867109
CrossRef PubMed

[3] Wiebers DO,

[4] Whisnant JP,

[5] Huston J 3rd., et al

[6] 2.↵

Etminan N,
Brown RD Jr.,
Beseoglu K, et al
. The unruptured intracranial aneurysm treatment score: a multidisciplinary consensus. Neurology 2015;85:881–89 doi:10.1212/WNL.0000000000001891 pmid:26276380
CrossRef PubMed

[8] Etminan N,

[9] Brown RD Jr.,

[10] Beseoglu K, et al

[11] 3.↵

Seibert B,
Tummala RP,
Chow R, et al
. Intracranial aneurysms: review of current treatment options and outcomes. Front Neurol 2011;2:45 doi:10.3389/fneur.2011.00045 pmid:21779274
CrossRef PubMed

[13] Seibert B,

[14] Tummala RP,

[15] Chow R, et al

[16] 4.↵

Molyneux AJ,
Kerr RS,
Birks J, et al
; ISAT Collaborators. Risk of recurrent subarachnoid haemorrhage, death, or dependence and standardised mortality ratios after clipping or coiling of an intracranial aneurysm in the International Subarachnoid Aneurysm Trial (ISAT): long-term follow-up. Lancet Neurol 2009;8:427–33 doi:10.1016/S1474-4422(09)70080-8 pmid:19329361
CrossRef PubMed

[18] Molyneux AJ,

[19] Kerr RS,

[20] Birks J, et al

[21] 5.↵

Mascitelli JR,
Oermann EK,
De Leacy RA, et al
. Predictors of treatment failure following coil embolization of intracranial aneurysms. J Clin Neurosci 2015;22:1275–81 doi:10.1016/j.jocn.2015.03.002 pmid:25986179
CrossRef PubMed

[23] Mascitelli JR,

[24] Oermann EK,

[25] De Leacy RA, et al

[26] 6.↵

Colby GP,
Paul AR,
Radvany MG, et al
. A single center comparison of coiling versus stent assisted coiling in 90 consecutive paraophthalmic region aneurysms. J Neurointerv Surg 2012;4:116–20 doi:10.1136/jnis.2011.004911 pmid:21990478
Abstract/FREE Full Text

[28] Colby GP,

[29] Paul AR,

[30] Radvany MG, et al

[31] 7.↵

Raymond J,
Roy D
. Safety and efficacy of endovascular treatment of acutely ruptured aneurysms. Neurosurgery 1997;41:1235–45; discussion 1245–46 doi:10.1097/00006123-199712000-00002 pmid:9402574
CrossRef PubMed

[33] Raymond J,

[34] Roy D

[35] 8.↵

Chalouhi N,
Dumont AS,
Hasan D, et al
. Is packing density important in stent-assisted coiling? Neurosurgery 2012;71:381–86; discussion 386–87 doi:10.1227/NEU.0b013e31825c36dd pmid:22569059
CrossRef PubMed

[37] Chalouhi N,

[38] Dumont AS,

[39] Hasan D, et al

[40] 9.↵

Sluzewski M,
van Rooij WJ,
Slob MJ, et al
. Relation between aneurysm volume, packing, and compaction in 145 cerebral aneurysms treated with coils. Radiology 2004;231:653–58 doi:10.1148/radiol.2313030460 pmid:15118115
CrossRef PubMed

[42] Sluzewski M,

[43] van Rooij WJ,

[44] Slob MJ, et al

[45] 10.↵

Chueh JY,
Vedantham S,
Wakhloo AK, et al
. Aneurysm permeability following coil embolization: packing density and coil distribution. J Neurointerv Surg 2015;7:676–81 doi:10.1136/neurintsurg-2014-011289 pmid:25031179
Abstract/FREE Full Text

[47] Chueh JY,

[48] Vedantham S,

[49] Wakhloo AK, et al

[50] 11.↵

Piotin M,
Blanc R,
Spelle L, et al
. Stent-assisted coiling of intracranial aneurysms: clinical and angiographic results in 216 consecutive aneurysms. Stroke 2010;41:110–15 doi:10.1161/STROKEAHA.109.558114 pmid:19959540
CrossRef PubMed

[52] Piotin M,

[53] Blanc R,

[54] Spelle L, et al

[55] 12.↵

Chalouhi N,
Jabbour P,
Singhal S, et al
. Stent-assisted coiling of intracranial aneurysms: predictors of complications, recanalization, and outcome in 508 cases. Stroke 2013;44:1348–53 doi:10.1161/STROKEAHA.111.000641 pmid:23512976
Abstract/FREE Full Text

[57] Chalouhi N,

[58] Jabbour P,

[59] Singhal S, et al

[60] 13.↵

Chalouhi N,
Starke RM,
Koltz MT, et al
. Stent-assisted coiling versus balloon remodeling of wide-neck aneurysms: comparison of angiographic outcomes. AJNR Am J Neuroradiol 2013;34:1987–92 doi:10.3174/ajnr.A3538 pmid:23639562
Abstract/FREE Full Text

[62] Chalouhi N,

[63] Starke RM,

[64] Koltz MT, et al

[65] 14.↵

Hong Y,
Wang YJ,
Deng Z, et al
. Stent-assisted coiling versus coiling in treatment of intracranial aneurysm: a systematic review and meta-analysis. PLoS One 2014;9:e82311 doi:10.1371/journal.pone.0082311 pmid:24454690
CrossRef PubMed

[67] Hong Y,

[68] Wang YJ,

[69] Deng Z, et al

[70] 15.↵

Tanemura H,
Ishida F,
Miura Y, et al
. Changes in hemodynamics after placing intracranial stents. Neurol Med Chir (Tokyo) 2013;53:171–78 doi:10.2176/nmc.53.171 pmid:23524501
CrossRef PubMed

[72] Tanemura H,

[73] Ishida F,

[74] Miura Y, et al

[75] 16.↵

Tateshima S,
Tanishita K,
Hakata Y, et al
. Alteration of intraaneurysmal hemodynamics by placement of a self-expandable stent: laboratory investigation. J Neurosurg 2009;111:22–27 doi:10.3171/2009.2.JNS081324 pmid:19267529
CrossRef PubMed

[77] Tateshima S,

[78] Tanishita K,

[79] Hakata Y, et al

[80] 17.↵

Lopes D,
Sani S
. Histological postmortem study of an internal carotid artery aneurysm treated with the Neuroform stent. Neurosurgery 2005;56:E416; discussion E doi:10.1227/01.NEU.0000147977.07736.66 pmid:15670395
CrossRef PubMed

[82] Lopes D,

[83] Sani S

[84] 18.↵

Geyik S,
Yavuz K,
Yurttutan N, et al
. Stent-assisted coiling in endovascular treatment of 500 consecutive cerebral aneurysms with long-term follow-up. AJNR Am J Neuroradiol 2013;34:2157–62 doi:10.3174/ajnr.A3574 pmid:23886748
Abstract/FREE Full Text

[86] Geyik S,

[87] Yavuz K,

[88] Yurttutan N, et al

[89] 19.↵

Sadato A,
Adachi K,
Hayakawa M, et al
. Effects of anatomic characteristics of aneurysms on packing density in endovascular coil embolization: analysis of a single center's experience. Neurosurg Rev 2016;39:109–14; discussion 114 doi:10.1007/s10143-015-0658-7 pmid:26223542
CrossRef PubMed

[91] Sadato A,

[92] Adachi K,

[93] Hayakawa M, et al

[94] 20.↵

Ozretić D,
Radoš M,
Pavliša G, et al
. Long-term angiographic outcome of stent-assisted coiling compared to non-assisted coiling of intracranial saccular aneurysms. Croat Med J 2015;56:24–31 doi:10.3325/cmj.2015.56.24 pmid:25727039
CrossRef PubMed

[96] Ozretić D,

[97] Radoš M,

[98] Pavliša G, et al

[99] 21.↵

Bouillot P,
Brina O,
Ouared R, et al
. Particle imaging velocimetry evaluation of intracranial stents in sidewall aneurysm: hemodynamic transition related to the stent design. PLoS One 2014;9:e113762 doi:10.1371/journal.pone.0113762 pmid:25470724
CrossRef PubMed

[101] Bouillot P,

[102] Brina O,

[103] Ouared R, et al

[104] 22.↵

Lawson MF,
Newman WC,
Chi YY, et al
. Stent-associated flow remodeling causes further occlusion of incompletely coiled aneurysms. Neurosurgery 2011;69:598–603; discussion 603–04 doi:10.1227/NEU.0b013e3182181c2b pmid:21430583
CrossRef PubMed

[106] Lawson MF,

[107] Newman WC,

[108] Chi YY, et al

[109] 23.↵

Gallas S,
Januel AC,
Pasco A, et al
. Long-term follow-up of 1036 cerebral aneurysms treated by bare coils: a multicentric cohort treated between 1998 and 2003. AJNR Am J Neuroradiol 2009;30:1986–92 doi:10.3174/ajnr.A1744 pmid:19679641
Abstract/FREE Full Text

[111] Gallas S,

[112] Januel AC,

[113] Pasco A, et al

[114] 24.↵

Yang H,
Sun Y,
Jiang Y, et al
. Comparison of stent-assisted coiling vs coiling alone in 563 intracranial aneurysms: safety and efficacy at a high-volume. Neurosurgery 2015;77:241–47; discussion 247 doi:10.1227/NEU.0000000000000765 pmid:25856112
CrossRef PubMed

[116] Yang H,

[117] Sun Y,

[118] Jiang Y, et al

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American Journal of Neuroradiology

Packing Density Necessary to Reach a High Complete Occlusion Rate in Circumferential Unruptured Intracranial Aneurysms Treated with Stent-Assisted Coil Embolization

Abstract

ABBREVIATIONS: